Removable denture



April 1937' J. WAHLBERG 2,078,647

REMOVABLE DENTURE Filed April 9, 1936 I Z1 INVENTOR. fy.% BY .fo/m wade/ ATTORNEYS Patented Apr. 27, 1937 UNITED S'i'ATEg PATENT OFFICE REMOVABLE DENTURE Application April 9, 1936, Serial No. 73,391

1 Claim.

This invention relates. to removable dentures and more particularly to pier connections for the same.

Heretofore in the use of removable dentures, difficulties have been experienced, some of which are due to structural arrangements whereby the tops of the dentures are open sufiiciently to permit the intrusion of articles of food, etc., and partially due to constructions wherein the resilient member or members holding the denture in place become worn, requiring renewal which can be accomplished only with excessive care and trouble.

An object of the invention is to provide a pier connection of such character that it can be man ufactured with a minimum of expense and labor and of such character as to be of the utmost eniciency in operation.

Another object of the invention is to provide a pier connection of such character that component parts thereof are of the utmost simplicity.

A further object of the invention is to provide a pier connection made up of a head and socket together with a tension member which extends substantially laterally across the head.

In carrying out the foregoing and other objects of the invention, use is made of connection members comprising T-shaped heads held in correspondingly shaped socket members. The T- shaped head has extending laterally across the face thereof, near the bottom, a shallow groove or slot in which is secured a bowed leaf spring member. The slot extends around the edges of the T-head and the ends of the leaf spring are curved to conform to the shape of the slots, whereby the curved portions of the leaf spring fit snugly within those portions of the slot in the rounded edges of the T-head. The bow in the leaf spring occurs substantially mid-way between the curved end portions of the spring so that in use the mid portion of the spring extends outwardly a slight distance beyond the face of the T-head. The socket in which the T-head fits is of such dimensions as to receive the T- head with the retaining spring with a fit which permits slight movement of the T-head in the socket. This movement is essential to simulate the slight movement of teeth during use thereof.

Other features, objects and advantages of the invention will become apparent by reference to the following detailed description of accompanying drawing illustrating the same, wherein Fig. 1 is a side elevation illustrating the invention as applied to and in use with removable dentures.

Fig. 2 is an enlarged perspective view, with some of the parts in section, of a T-head embodying the invention.

Fig. 3 is a section taken substantially on the line 33 of Fig. 2.

Fig. 4 is a section taken substantially on the line l4 of Fig. 3.

Fig. 5 is a perspective view of a socket used in the invention; and

Fig. 6 is a perspective view of a tension member used in the invention.

Referring now to the drawing, Ill indicates generally socket members adapted to be embedded in spaced pier teeth H as illustrated more clearly in Fig. 5 wherein it will be seen that-the member has a'substantially T-shaped cavity 12 for the reception of a T-head member, and is provided with a bottom M for limiting downward movement of the T-head member. A T-head member indicated generally at It in Fig. 2 comprises a neck portion l and a cross-head portion 16. This cross-head portion It; has a slot ll extending laterally across the face thereof and around the edges thereof. Preferably, the slot I1 is spaced near the bottom of the cross-head portion for reasons to be explained later.

The retaining or tension member comprises a leaf spring of size and shape to fit closely in the slot H. In order that this tension member can be held in the slot 11, the ends thereof are curved as at 2| to fit in those portions of the slot I1 extending around the curved edges of the cross-head IS. The expanse of leaf 20 between the curved ends 2| is bowed slightly so that normally the mid-portion thereof extends outwardly from the face of the cross-head l6 as shown in Fig. 2 and in the section illustrated in Figs. 3 and 4. The longitudinal edges of the spring 20 are rounded to facilitate introduction of the T-head and spring in a socket.

The cross-head I6 is made of a shape corresponding to the internal shape of the cavity in the socket H], but of slightly smaller size so that a minute clearance exists between the surface of the cross-head and a wall of a cavity and between the edges of the cross-head and the rounded walls of the socket. While the crosshead shown in the drawing has been illustrated and described as having a single slot extending laterally thereacross, it is contemplated that should conditions warrant, a second slot could be provided in the surface of the cross-head spaced upwardly from the slot shown.

The operation and use of the invention is substantially as follows: Sockets II] are embedded in spaced pier teeth as shown in Fig. 1. To the opposite sides of a removable denture made up of teeth 30 are secured T-head members M in such fashion that the cross-heads thereof ex- 5 tend beyond the edges of the denture. Ordinarily, the T-head is of greater length than is necessary for the purposes and, accordingly, it is usually necessary to grind away a top portion of the T-head sufiicient to cause the same to have its upper edge flush with the top of the socket when the denture is in place. Since the retaining member is located near the bottom of the T-head, the removal of some of the T-head at the top thereof will not interfere with the operation of the retaining member. .When the two T-heads have been properly sized to fit their respective sockets, the denture is then in condition to be locked removably in place. To accomplish this, a tension or retaining member is snappedto fit in its groove in the cross-head portion of the T-head. With the tension members on each T-head, the denture may then be inserted in place between the pier teeth. Due to the slight bow in the tension member, the mid-portion of each tension member bears frictionally against the inner wall of the socket adjacent the face of the cross-head portion. This condition is shown clearly in Figs. 3 and 4.

A denture held in place with connections embodying the present invention has performance closely simulating that of natural teeth. In other Words, the denture is capable of the slight rocking movement between the pier teeth as would occur in natural teeth therebetween. Such rocking is permitted by the minute space between the cross-head portion of the T-head and the retaining socket. At the same time the denture is retained between the pier teeth by the tension, or friction due to the bowed leaf springs. Also, the denture made in accordance with the foregoing possesses the advantage that the top of the socket is substantially completely closed so that the chances of the entrance of foreign matter into the socket are effectively eliminated. 45 The space between the cooperating parts is so minute as to preclude the entry of any appreciable harmful matter.

The pier connections described herein have the advantages of simplicity of manufacture, 5O simplicity of assembly and disassembly. As before mentioned, the tension or retaining member is secured to the T-head simply by snapping the curved ends of the tension member around the curved edges of the cross-head portion so that 55 the major portion of the tension member is entirely within the slot provided therefor. Should a tension member, after use, lose its resiliency,

or should it be necessary to substitute one tension member for another for any reason, the tension member can be quickly and easily removed from the T-head by means of a suitable simple tool to engage one end of the tension member and spring the same out of the socket. It is evident that another tension member could then be assembled with the T-head.

As before stated, the invention provides a connection which serves to hold a denture in place yet permits the denture tomove in the same fashion as a normal tooth would move. The importance of this arrangement will be evident when it is appreciated that each tooth is cushioned in a socket of resilient membrane so that during mastication, .a tooth is capable of some slight rocking movement. Accordingly, since a denture can move slightly relative to the pier teeth, the strain which would be set up in the pier teeth by a bridging denture rigidly connected thereto is effectively eliminated. Due to the construction of the connection members it is possible to have these members made of relatively light material so that a minimum of space must be removed from pier teeth to accommodate the sockets.

From the foregoing it will be seen that the present invention provides features of novelty not found in pier connections previously used, and that the advantages set forth hereinbefore are such as are peculiar to the described construction. t is to be understood, however, that the invention is not to be limited to the illustrated embodiment but is to be limited only by the following claim.

I claim:

A pier connection for removable dentures comprising a socket having a substantially T-shaped head receiving cavity therein, a substantially T- shaped head member to fit in said socket, said head member having rounded longitudinal edges, said head member having a slot extending laterally thereacross and around the edges thereof, a leaf-spring of thickness substantially equal to the depth of said slot, said leaf-spring having the ends thereof bent to fit in the portions of the groove extending around the edges of the T- shaped member with a snap fit to lock said spring in the slot, said snap fit engagement between the ends of the spring and the T-shaped member being the sole connection between such parts; said leaf-spring being bowed outwardly intermediate the edges of the fiat face of said T-shaped member, said bowed part of said spring being the sole part thereof extending beyond the surface of said T-shaped member.

JOHN WAHLBERG. 

